Method and device for exchanging tools on machines having reciprocating movement

ABSTRACT

In a method for exchanging tool sets to a machine having a reciprocating movement and including locking means for the parts of each tool set, the tool parts, in advance of insertion into the machine, are positioned and releasably retained in a tool holder. The tool holder, carrying the parts, is then inserted into the machine and the locking means are operated to lock the tool parts in the machine while the tool parts are still in the holder. The holder is then released from the tool parts and withdrawn from the machine. The holder includes adjustably superposed forked arms, each engageable with a respective tool part, with each arm of the fork having releasable detent means cooperable with the associated tool part. Either the arms of the fork or the releasable detent means may be resilient to provide for ready engagement of the holder with the tool parts and ready disengagement therefrom.

United States Patent Leibinger [451 July 25, 1972 54] METHOD AND DEVICE FOR 3,309,765 3/l967 Kirsten ..29/401 EXCHANGING TOOLS 0 MACHINES 3,368,625 2/1968 Kirkham ..29/2ll C X HAVING RECIPROCATING Primary Examiner-Thomas H. Eager MOVEMENT Attorney-McGlew and Toren [72] Inventor: Berthold Leiblnger, Gerhngen, Germany I 57] ABSTRACT ['73] Asslgnee: 23 & Swugamwellmdorf Gerln a method for exchanging tool sets to a machine having a y reciprocating movement and including locking means for the [22] Filed: Oct. 22, 1970 parts of each tool set, the tool parts, illi advance of insertion into the machine, are positioned and releasably retained in a [21] App! 82,992 tool holder. The tool holder, carrying the parts, is then inserted into the machine and the locking means are operated to [30] Foreign Applicafion Priority Dam lock the tool parts in the machine while the tool parts are still in the holder. The holder is then released from the tool parts Nov. 3, 1969 Germany ..P l 55 1 and withdrawn from the machine. The holder includes adjustably superposedforked arms, each engageable with a [52] U.S. Cl. ..'..29/400, 29/200 D, 29/208 C respective tool part, with each arm of the fork having releasa- [51] lnt.Cl. ..B23p 17/00, 823p 19/04 ble detent means cooperable with the associated tool part. [58] Field of Search ..-.29/400, 200 D, 200 B, 429, Either the arms of the fork or the releasable detent means may 29/21 1 D, 208 C be resilient to provide for ready engagement of the holder with the tool parts and ready disengagement therefrom. 56 f d 1 Re erences Cite. 16 Claims, 8 Drawing Figures UNITED STATES PATENTS 2,540,836 2/195] Seybold ..29/200 D PATENTEU JUL25 I972 SHEET 1 (IF 3 INVENTOR. B RT LEIBINGER Wcew who 75 m ATTO R N EYS PATENTED JUL25 19 sum 2 0F 3 Fig 3 IN VEN TOR- RTHOLD LEIBINGER PATENTEU JUL25 m2 sum 3 or 3 INVENTOR. BERTHOLD LEIBINGER BY WW mo 7529072 ATTORNEYS BACKGROUND OF THE INVENTION Machines having a reciprocatingvmovement or motion are arranged to have different tool sets exchangeably or interchangeably mounted therein. Each tool set can comprise, for example, a punch or nibbling die with a cooperating bottom die, a stamping tool with top and bottom dies, and similar sets. The punching tool, for example, usually is arranged in an upper tool carrier, and the associated bottom die in a lower tool carrier. This also holds true for so-called nibbling machines and the like. in order to change the tool set, the punch is replaced first and then the bottom die is replaced. To do this, the operator must reach into the machine, and this requires corresponding safety measures. There is also a risk that, in exchanging tool sets, tool parts which do not properly fit or mate with each other will be inserted, and this can lead to damage of expensive tool parts and also to damage of the machine.

SUMMARY or THE lNVENTlON This invention relates to exchanging and interchanging tool sets relative to a machine having a reciprocating movement and, more particularly, to a novel, improved, safer and more efficient method and apparatus for effecting such exchange or interchange, and substantially reducing the time required therefor.

In order to provide an improved method and apparatus greatly reducing the time required to change tool sets, and to eliminate the necessity of providing safety devices, which are required only during changing of the tools, in accordance with the invention, the tool parts of each set, before insertion into the machine, are positioned in a holder. The parts are retained in the holder by suitable retaining elements, and the holder is then inserted into the machine. After such insertion, suitable locking means of the machine retain the parts of the tool set in the machine. The retaining elements of the holder are then loosened and the holder is withdrawn from the machine.

Frequently, punching machines, nibbling machines, etc., also include other tool parts such as, for example, a stripper, pressure pads, etc. For exchanging tool sets with respect to these latter machines, in accordance with the further development of the invention, any required additional component, such as a stripper, pressure pads, etc., are also inserted in the holder and retained therein by means of corresponding elements of the holder.

In accordance with the special preferred embodiment of the invention, the retaining elements of the holder are moved automatically into their release position, and the locking means of the machine are moved automatically into their tool part locking positions. This can be effected by having the holder actuate a switch, open an air pressure or oil pressure valve of a servo-mechanism, or merely strictly mechanically actuate the locking means of the machine, for example, through the medium ofa linkage or the medium of levers.

The invention device, for use with a machine having a punch and a bottom die, is designed as a holder provided with two superposed retaining arms, one arm being assigned to one part of the tool set and the other arm to the other part of the tool set. This holder is comparable to an insertion box which is loaded or charged before it is introduced into the machine or apparatus. For use with machines having additional components, such as strippers, etc., the invention device is designed as a holder with three or more superposed arms, with the center arm being associated with the stripper or the like and the two outer arms with one or the other part of the two parts of the tool set. t

As a further feature of the invention, the holder has clamping and locking means for the individual parts of the tool set and for the stripper, if the latter is provided. These clamping and locking means insure a satisfactory fit of these parts in the holder, as well as the correct and accurate association of the parts. Thus, the transfer to the gripping elements and holding elements of the machine can occur without trouble, and the parts to be exchanged or interchanged arrive exactly at the correct location of the machine. At this point, it should be emphasized explicitly that, in cases where the application speaks of assembly, insertion, retaining, etc., these terms naturally apply for the opposite processes or operations, such as disassembly, removal, release, etc.

A further advantage of the invention is that the retaining arms are fork-shaped, and the fork prongs embrace the part to i be retained laterally, in order to form a holding device or clamping device, the fork prongs bearing particularly on two plane-parallel surfaces of the associated tool part. In a variant of the invention, at least one of the prongs of each fork has an inwardly protruding bolt, stud, strip, etc., engaging a corresponding depression in the part to be retained, and at least one prong or retaining bolt, etc., can be moved transverse to the longitudinal extent of the fork prongs. lf studs or short bolts are used, it is sufficient if one of the fork arms is so elastic that it can be bent resiliently laterally. lf relatively rigid fork prongs are used, the retaining studs can be designed preferably as ball snaps.

In another variant of the invention, at least one of the retaining bolts and the like is held in its retaining position by means of a spring loaded pivotal lever. This lever then can be turned by hand, or by a corresponding control device, when a certain connecting position or deconnecting position is reached, in order to assume a holding position or a release position, respectively.

As a further feature of the invention, at least one of the retaining bolts or the like can be controlled by auxiliary power, the control of this auxiliary power being effected arbitrarily by hand, or positively when a certain relative position of the holder and the machine is attained. In a particularly advantageous manner, a control or switching device, released by the holder, is used for the control of the auxiliary power in the machine.

Since the holders should be universally applicable, if possible, even though the parts to be inserted can have different sizes and dimensions, in accordance with a further feature of the invention, at least one retaining arm is adjustable relative to another retaining arm, particularly with respect to height or relative vertical spacing. The simplest, and thus the least expensive, realization is the arrangement of the forks on a threaded spindle with corresponding supporting nuts and lock nuts.

Another feature of the invention resides in that the tool parts and, when provided, the stripper, etc., have at least one gripping surface or groove for receiving a corresponding chucking member with a chucking wedge which can be displaced in the direction of the tool movement in the machine. As soon as the holder has been introduced completely into the machine, these chucking wedges are activated to press the parts to be retained against corresponding stop surfaces of the machine or of the tool carriers. lnversely, the chucking wedges are withdrawn only when the parts to be removed from the machine are exactly above the seats of the holder to carry the parts. In this connection, it is particularly advantageous that the tool, the bottom die, and the stripper, etc., have conical parts cooperating with corresponding counterconical parts of the machine. The inter-cooperating conical parts must be arranged to permit insertion and removal transversely of the longitudinal axis of the cones.

As still a further feature of the invention, the movement of the holder is controlled by an automatic tool changing device. Thus, several holders can be used in connection with a magazine which performs automatically a change of tools after one or several operations. The control can be effected by punch cards, magnetic tapes, etc.

An object of the invention is to provide an improved method for exchanging and interchanging tool sets relative to a machine having a reciprocating movement.

Another object of the invention is to provide an improved apparatus for carrying out this method.

A further object of the invention is to provide such a method and apparatus in which the time required to exchange or interchange tools is greatly reduced.

Another object of the invention is to provide such a method and apparatus with which safety devices, necessary only during changing of tools, are no longer necessary.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing:

BRIEF DESCRIPTION OF THE DRAWING In the Drawing:

FIG. 1 is a side elevational view of a holder embodying the invention before insertion into a machine whose tool carrier is illustrated in vertical section;

FIG. 2 is a view, similar to FIG. 1, illustrating the holder in the limiting insertion position;

FIG. 3 is a view, similar to FIG. 2, illustrating the locking position ofa tool set including a stripper;

FIG. 4 is a view, similar to FIG. 3, illustrating the machine in operating position and with the holder removed;

FIG. 5 is a side elevation view of the holder per se;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is a side elevation view of a bottom die; and

FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7.

DESCRIPTIONOF THE PREFERRED EMBODIMENTS As best seen in FIG. 5, a tool set holder 1, embodying the invention, has three superposed tool part retaining arms 2, 3 and 4. Upper arm 4 serves to carry a punch 5, center arm 3 serves to carry a stripper 6, and lower arm 2 serves to carry a bottom die 7. Punch 5, bottom die 7, and stripper 6 form a tool set. Upon occasion, it is customary not to include any stripper in the tool set.

As best seen in FIG. 6, the retaining arms are fork-shaped, with the fork prongs 8 and 9 embracing the tool part to be retained laterally thereby. Parallel slots 12 are formed in each tool part to provide stop surfaces 10 and 11 for the inner surfaces of the fork prongs, and the center of each slot 12 is formed with a conical retaining bore or detent 13.

Bores 13 are engageable by the respective ends 14 and 15 of retaining bolts 16 and 17 which extend inwardly through each fork prong. In theembodiment illustrated in FIG. 6, retaining bolt 16 is fixedly mounted whileretaining bolt 17 is displaceable, in the direction of the double arrow 18, in a manner which has not been indicated. If holder I is moved in the direction of arrow 19 toward the tool part to be received, fork prongs 8 and 9 move elastically outwardly in the direction of the arrows 20, 21, due to the inwardly protruding retaining bolt ends 14 and 15. This is particularly the case when both supporting bolts are secured fixedly in the associated fork prongs. After bolt ends 14 and 15 have engaged in bores or detents l3, fork prongs 8 and 9 return to their starting position and retain the part to be carried. The spacing between inner faces 22 and 23 of the fork prongs corresponds to the spacing between the bottom surfaces 10 and II of the grooves 12. In place of retaining bolts 16 and 17, spring-loaded balls, such as ball snaps, can be used, and this makes the lateral elastic yielding of the fork prongs, during assembly thereof with the part to be carried, unnecessary.

As viewed in FIG. I, holder 1, carrying a punch 5, stripper 6 and bottom die 17, is introduced into the opening 25 of the machine in the direction of the arrow 24. When the limiting position, represented in FIG. 2, is reached, chucking pieces 26, 27 and 28, shown in FIG. 3, are moved in the direction of arrows 29 and 30. The chucking wedges 31, 32 and 33 as sociated with chucking pieces 26, 27 and 28 assure conical parts 34, 35 and 36 molded, respectively, on the punch, the bottom die and the stripper, being pressed into corresponding counter-conical seats of the tool carriers of the machine. After the tools have been locked in position, holder 1 is withdrawn from the machine. The relative positions after withdrawal are indicated in FIG. 4, where the machine is ready for use.

To change a tool, a bottom die, or a stripper, or all three, the empty holder 1 is inserted into the machine in the direction of arrow 24 of FIG. 1 until retaining bolts 14 and 15 have snapped into the corresponding detent recesses 13. Subsequently, chucking pieces 26, 27 and 28, with their associated wedges, are withdrawn in a direction opposite to the arrows 29 and 30. Unlocking of the tool parts is thus completed, and holder 1, together with any tool parts carried thereby, can be withdrawn in a direction opposite to arrow 24. Another tool set can then be inserted into the machine by another holder 1, having the tool parts already assembled therewith, or by the same holder 1 used to extract the tool parts but now having new tool parts mounted therein.

As shown in FIG. 5, bottom fork 2 is integral with holder 1, while the two upper forks 3 and 4 can be adjusted upwardly and downwardly, as well as laterally, along a threaded bolt 37. Nuts 38 and 39 are provided for locking forks 3 and 4 in adjusted position but, for the sake of clarity, the nuts associated with fork 4 have not been represented.

It should be noted, that the chucking pieces and associated chucking wedges must be able to travel a certain distance conjointly before the chucking effect is initiated. To this end. each chucking wedge is provided with an oblong slot which limits this movement, toward both ends, by means ofa stationary pin or the like. The longitudinal displacement of parts 26, 27 and 28, and parts 31, 32 and 33, is necessary in order to be able to mount the parts of the tool set, with a stripper or the like, in an unhindered manner.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. A method for inserting and removing tool sets, each including at least two cooperable tool parts, relative to a machine having a reciprocating movement and including respective locking means for the tool parts, said method comprising the steps of positioning the tool parts, in advance of insertion into the machine, in a tool holder; releasably retaining the tool parts in the tool holder; inserting the holder into the machine; operating the locking means to lock the tool parts, while the latter are still in the holder, in the machine; releasing the holder from the tool parts; and withdrawing the holder from the machine.

2. A method as claimed in claim 1, including additionally positioning a stripper in the tool holder in advance ofinsertion into the machine.

3. A method as claimed in claim 1, including automatically releasing the holder from the tool parts when the latter have been inserted in the machine; and automatically operating the locking means to lock the tool parts in the machine.

4. Apparatus for inserting and removing tool sets, each including at least two cooperable tool parts, relative to a machine having a reciprocating movement and including respective locking means for the tool parts, said apparatus comprising a tool holder including at least two superposed arms, with the uppermost arm being arranged to releasably retain one tool part and the lowermost arm being arranged to releasably retain the other tool part.

5. Apparatus as claimed in claim 4, in which said holder comprises three superposed arms, the intermediate arm being arranged to releasably retain a stripper or the like associated with the two-part tool set whose parts are releasably retaina ble in the upper and lower arms ofthe tool holder.

6. Apparatus as claimed in claim 5, in which each upper and lower arm of said tool holder has clamping and locking means for the associated tool part; said intermediate arm having clamping and locking means for a stripper or the like associated with the tool set.

7. Apparatus as claimed in claim 4, in which each arm of said tool holder is a fork-shaped retaining arm; the prongs of each fork being constructed and arranged to embrace the tool part to be held thereby and being engageable on two substantially plane parallel surfaces of the associated tool part.

8. Apparatus as claimed in claim 7, in which at least one prong of each fork has detent means releasably engageable with a corresponding detent of the tool part to be carried; at least one of the fork prongs having the detent means or the detent means being movable transverse to the longitudinal extent of the fork prongs.

9. Apparatus as claimed in claim 8, in which said detent means are ball snaps.

10. Apparatus as claimed in claim 8, in which said detent means are retaining bolts; at least one retaining bolt being held in position by a spring-loaded pivotal lever.

11. Apparatus as claimed in claim 8, in which at least one detent means is controlled by auxiliary power.

12. Apparatus as claimed in claim ll, including control means controlling the auxiliary power; said control means being actuated by said holder upon insertion into the machine.

13. Apparatus as claimed in claim 4, in which the relative spacing of said retaining arms is adjustable.

14. Apparatus as claimed in claim 4, in which said tool parts and associated components are formed with at least one gripping surface; said locking means comprising chucking pieces each having a chucking wedge operatively associated therewith; said chucking pieces and said chucking wedges being mounted in said machine for movement in the direction of the tool movement of the machine.

15. Apparatus as claimed in claim 14, in which said tool parts and the associated components of each set have conical surfaces cooperable with corresponding counter-conical seats of the machine.

16. Apparatus as claimed in claim 4, including an automatic tool changing device controlling movement of said holder relative to the machine.

* i l= l 

1. A method for inserting and removing tool sets, each including at least two cooperable tool parts, relative to a machine having a reciprocating movement and including respecTive locking means for the tool parts, said method comprising the steps of positioning the tool parts, in advance of insertion into the machine, in a tool holder; releasably retaining the tool parts in the tool holder; inserting the holder into the machine; operating the locking means to lock the tool parts, while the latter are still in the holder, in the machine; releasing the holder from the tool parts; and withdrawing the holder from the machine.
 2. A method as claimed in claim 1, including additionally positioning a stripper in the tool holder in advance of insertion into the machine.
 3. A method as claimed in claim 1, including automatically releasing the holder from the tool parts when the latter have been inserted in the machine; and automatically operating the locking means to lock the tool parts in the machine.
 4. Apparatus for inserting and removing tool sets, each including at least two cooperable tool parts, relative to a machine having a reciprocating movement and including respective locking means for the tool parts, said apparatus comprising a tool holder including at least two superposed arms, with the uppermost arm being arranged to releasably retain one tool part and the lowermost arm being arranged to releasably retain the other tool part.
 5. Apparatus as claimed in claim 4, in which said holder comprises three superposed arms, the intermediate arm being arranged to releasably retain a stripper or the like associated with the two-part tool set whose parts are releasably retainable in the upper and lower arms of the tool holder.
 6. Apparatus as claimed in claim 5, in which each upper and lower arm of said tool holder has clamping and locking means for the associated tool part; said intermediate arm having clamping and locking means for a stripper or the like associated with the tool set.
 7. Apparatus as claimed in claim 4, in which each arm of said tool holder is a fork-shaped retaining arm; the prongs of each fork being constructed and arranged to embrace the tool part to be held thereby and being engageable on two substantially plane parallel surfaces of the associated tool part.
 8. Apparatus as claimed in claim 7, in which at least one prong of each fork has detent means releasably engageable with a corresponding detent of the tool part to be carried; at least one of the fork prongs having the detent means or the detent means being movable transverse to the longitudinal extent of the fork prongs.
 9. Apparatus as claimed in claim 8, in which said detent means are ball snaps.
 10. Apparatus as claimed in claim 8, in which said detent means are retaining bolts; at least one retaining bolt being held in position by a spring-loaded pivotal lever.
 11. Apparatus as claimed in claim 8, in which at least one detent means is controlled by auxiliary power.
 12. Apparatus as claimed in claim 11, including control means controlling the auxiliary power; said control means being actuated by said holder upon insertion into the machine.
 13. Apparatus as claimed in claim 4, in which the relative spacing of said retaining arms is adjustable.
 14. Apparatus as claimed in claim 4, in which said tool parts and associated components are formed with at least one gripping surface; said locking means comprising chucking pieces each having a chucking wedge operatively associated therewith; said chucking pieces and said chucking wedges being mounted in said machine for movement in the direction of the tool movement of the machine.
 15. Apparatus as claimed in claim 14, in which said tool parts and the associated components of each set have conical surfaces cooperable with corresponding counter-conical seats of the machine.
 16. Apparatus as claimed in claim 4, including an automatic tool changing device controlling movement of said holder relative to the machine. 